Electric clock



' March 14, 1939. c, F MWNEKER 2,150,516

ELECTRIC CLOCK Filed- Dec; 50, 1935 2 Sheets-She?- l INVENTOR CARLISLE F. MINNEKER BY 'WAM A WM WWW A TTORNE YS March 14, 1939. c WNNEKER 2,150,516

ELECTRIC CLOCK Filed Dec. 50, 1935 2 Sheets-Sheet 2 FIG.5.

INVENTOR CARLISLE F. MINNEKER m W W I ATE ORNEYS Patented Mar. 14, 1939 UNITED STATES PATENT/OFFICE ,j

' ELECTRIC cLocx Carlisle nmnneke netmn, Mien.- Application December 30, 1935, Serial No. 56,802 I :6 Claims. (01.. 58-28 1 T f This invention relates generally to cloclr 'r'ne'chanism and refers more particularly to improvements in electrically operated clock mechanism.

One of the principal objects of this invention consists in the provision of a relatively simple,

' inexpensive clock mechanism distinguished by the fact that the power impulse is delivered to the balance wheel by the action of the main spring on the escape lever instead of by the arma-' ture of the electromagnet. In accordance with hand operating ratchet and accompanying re,-'

duction gearing are actuated during'the'interval the armature of the electromagnet is released or, in other words, these instru'mentalities are not connected to the escape mechanism and the bal ance wheel during thelpower stroke. rangement, as well as the features specified in the cluding the balance wheel, are not affected by the highly variable resistances normally existing in the reduction gearing operativly connecting the ratchet to the clock hands.

The foregoing, as well as other obiects,'wlll be made more apparent as this description'proceeds,

especially when considered in connection withthe r accompanying drawings, wherein:

Figure 1 is a diagrammatic view of the clock mechanism showing the several parts of the same in a position these parts assume when the mechanism is at rest;

Figure 2 is'a view similar to Figure- 1 showing the several parts of the mechanism in a different position;

showing the several parts of the clock mechanism in still another position;

Figure 4 is a cross sectional view taken substantially on the plane indicated by the line 4-4 of Figure 3; and

Figure is a sectional view taken substantially on the plane indicated by the line 5-5 of Fig-' ure 3. 1

Referring now more in detail to the drawings, it will be noted that there is illustrated in the severalviews, a balance wheel I0 secured to a impulse to the balance This ar- I shaft II mounted in the usual manner on the clock plates (not'shown'l for oscillation, and actuated by the conventional hair spring designated in Figure 5 by'the reference character l2. Fixed to the balance wheel ID at a point spaced a predetermined distance from the axis of the shaft I l is an impulse pallet l3 andthe latter cooperates with escape mechanism It to impart the power wheel required to tension the hair spring [2.

The escape mechanism [4 may be identified as of the chromometer type, sin'cethe escape lever [5 of this mechanism is disconnected from the balance wheel except when delivering 'a power impulse to the latter wheel through the pallet l3. In detail, the escape lever i5 is securedinterme- 'diate the'ends thereof to a shaft IGsupported in any suitable manner for rocking movement :and

, actuated by ainain spring I 1 having one end suitably secured to'the shaft l6 and havingthe oppo site end anchored to one of the clock plates (not shown) by a pin' l8. Upon reference to Figures 1 to Sinclusive, it will be noted that the inner end 19 of theescape'lever is located in the path of travel of the 'impu lse pallet I3 on the balance preceding paragraph, render it possible to secure extremely accurate performanceof the clock, since with the same, the escape mechanism, in-

the arrow 20 in Figure 2, to its extreme position.

It will, of course, be understood that in the aforesaid position of the balance wheel or impulse pallet H, the escape lever l5 has previously been moved to the position shownin Figure 2, wherein the main spring I! is tensioned and the inner end of the escape lever is locked.

In the present instance, the lock for the-escape lever comprises a substantially wedge shaped stone 2| mounted upon a horn 22 and cooperating with a hook-shaped projection 23 on the escape lever 15 to hold the latter in theposition thereof shown in Figure 2. The horn 22 is secured to a leaf spring Mintermediate'the ends of the latter and one end of the spring'is fixedly supported in the manner designated by the reference character Figure 3 is also a view similar to Figure 1 25. The opposite end of the spring projects beyond the horn 22 and is adapted to be engaged by a; discharge pallet 26 secured to the shaft H of, the balance wheel. The apex 21 of the wedgeshaped stone is positioned adjacent the spring 24 and the extremity of the projection 23 is provided with a cam face 28 adapted to ride on the surface 29 of the stone 2| as the escape lever I5 is moved will flex the spring 24 sufficiently to permit the cam face 23 of the projection to move beyond the apex 21, whereupon return of the leaf spring 24 locates the extremity of the projection 23 at the 5 underside of the stone, in the manner shown in Figure 2.

It will be noted from Figure 2 that the relationship between the discharge pallet 25 and the impulse pallet 13 is such that the former is 10 cated in advance of the letter when the balance wheel I B is moving in the direction indicated by the arrow 20 in Figure 2. The arrangement is such that the discharge pallet 26 engages the free end of the spring 24 prior to engagement of 15 the impulse pallet l3 with the escape lever l5, and in so doing, flexes the free end of the spring 24 a sufficient distance in a direction away from the horn 22 to permit the discharge pallet to pass "from the right hand side of the spring, as viewed in Figures 1 and 2, to the left hand side of the same. In this connection, attention may be called to the fact that movement of the horn 22 with the free end of the spring 24 is prevented by means of a banking pin 30 positioned to form a 25 stop for the horn 22.

When the discharge pallet has assumed the position aforesaid on the left hand side of the free end of the spring 24, the impulse pallet l3 engages the upper side of the escape lever l5 and the balance wheel is moved by the hair spring I2 in the opposite direction, or in the direction of the arrow 31 in Figure 3. Initial movement of the balance wheel in in this latter direction effects a movement of the free end of the spring 24 in the same direction by the discharge pallet 26 and the extent of this movement is sufficient to release the extremity of the projection 23 from the underside of the stone 2i. As soon as the escape lever is released from the stone H, the same is moved in the direction of the arrow 32 by the energy previously stored up in the main spring l1, and since the impulse pallet l3 on the balance wheel is in engagement with the upper side of the escape lever, it necessarily follows that the latter will deliver a power impulse to the balance wheel l0.

Thus, from the above description of the escape mechanism, it will be apparent that the escape lever is operatively connected to the balance wheel only during the time the same delivers a power impulse to the balance wheel and at all other times, is disconnected from the wheel. This arrangement is extremely important in that the less interference offered to the proper operation of the balance wheel, the more accurate the clock mechanism.

In the present instance, the escape lever i5 is moved from the position thereof shown in Figure 1, to the position thereof illustrated in Figure 2, to tension the main spring I! by an elec tromagnet 33, supported in any suitable manner in the clock casing (not shown) and connected in the usual manner to a source of electrical energy. The magnet 33 is provided with an armature 34 pivotally supported intermediate its ends as at 35 and normally urged to its inoperative position, or in a direction away from the poles of the magnet by means of a spring 36. As will be observed from Figures 1 to 3 inclusive, the inner end of the spring is fixed to the armature 34 adlament the pivot 35, while the free end of the spring has a bearing engagement with a retaining pin 31 fixedly supported by the clock plate. The extent of movement of the armature 34 away from the pole pieces is determined by means of a banking pin 38, also fixed to the clock plate comes to rest on the pole pieces.

and engageable with the outer extremity of the armature. Mounted upon, but insulated from the inner end of the armature, is a switch contact 39 adapted to cooperate with a contact 40 secured to the outer end of the escape lever l5 by means of a leaf spring 4|. As shown in Figure l, the contact 39 is electrically connected to one end of the coil A of the magnet 33 by a conductor B, and the contact 40 is electrically connected to the escapement lever l5 by the spring 4|. The escapement lever is electrically connected to a pin C through the medium of the spring I1 and the pin C is grounded, as at D. It will also be noted from Figure 1 that the free end of the cell A is electrically connected to the adjacent end of the coil E of the electromagnet and the opposite end of this coil is connected to a source of electrical energy, such as a battery F having the negative side grounded, as at G. The arrangement is such that when the escape lever [5 completes its power stroke under the action of the main spring H, the contact 40 engages the cooperating contact 39 on the armature 34 and closes a circuit to the electromagnet. As a result, the armature 34 is swung about the pin 35 in the direction of the arrow 42 and, in so doing, swings the escape lever l5 to the position thereof shown in Figure 2. This latter function is accomplished by engagement of the inner end of the armature with a projection 43, extending iaterally from the escape lever I5. The circuit to the electromagnet is opened in timed relation to movement of the escape lever l5 by movement of the contact 40 in a direction away from the contact 39 through the medium of an adjusting screw 44 mounted on the inner end of the armature in a position to engage the breaker arm 45 secured to the escape lever shaft l5. In actual practice, the circuit to the electromagnet is broken substantially at the interval the latching face on the escapement lever registers with the cooperating latching face on the stone 2! and before the armature of the electromagnet However, the momentum of the escapement lever may carry the latching face on the latter beyond the stone, in which event the actual latching operation does not take place until the escapement lever is returned or moved in the opposite direction by the spring l1. It will, of course, be understood that the escapement lever is interrupted on its return movement by engagement of the latching face on the end 28 of the lever with the adjacent face of the stone 2|. As will be evident from the foregoing, the escapement lever remains in its latched position until the discharge pallet 26 is operated by the balance to disengage the stone 2| from the escapement lever.

As soon as the circuit to the armature is broken. the spring 36 functions to instantaneously swing the armature 34 about the pivot 35 in a direc tion away from the pole pieces of the magnet and this movement of the armature operates the clock hands (not shown) through the medium of a ratchet 48. As shown in Figures 1 to 3 inclusive, the inner end of the armature has secured thereto, a driving spring 41 having a return curved portion at the free end engageable with the teeth on the ratchet wheel. The arrangement is such that when the spring 36 releases the armature 34, the ratchet wheel is advanced one tooth and as the armature is moved in the opposite direction toward the pole pieces of the electromagnet, the free end of the driving spring is moved into operative position with the next a,iao,o1e

succeeding tooth on the ratchet. Reverse movement of the ratchet wheel is prevented by means of a retaining spring 48 having one end secured in any suitable manner to theclock case and having the opposite end positioned'for engagement with the shouldered surfaces of the ratchet teethon the wheel in the manner clearly shown in Figures 1 to 3 inclusive.

It will be observed from the foregoing, that the ratchet wheel 46- and reduction gearing (not shown) connecting the ratchet wheel with the hands of the clock are actuated solely by the armature return spring 36 and having no connection whatsoever to the escape mechanism. As a matter of fact, the escape mechanism, including the main spring I1, is entirely independent of the armature and this fact, together with theiact that the escape lever is free from connection with the balance wheel l0, except during the power stroke, results performance of the clock. This will be readily understood when considering that, by reason of the above construction, the highly variable resistances naturally present in the ratchet 46 and associated reduction gearing has absolutely no efiect whatsoever upon the successful operation of the escape mechanism.

Operation I the clock is connected in an electric circuit, the

electromagnet is immediately energized due to the fact that the contact 40, carried by the spring 4|, is in engagement with the contact 39 on the armature. Energization of the electromagnet 33 causes the armature 34 to swing in the direction of the arrow 42 and this motion of 'the magnet is transmitted to theescape lever l5 effecting a movement of the latter to the position thereof shown in Figure 2, wherein the same is locked by the stone 2| carried by the horn 22. As soon as the escape lever is locked, in the position thereof shown in Figure 2, by the stone 2|, the circuit to the electromagnet is opened by the action of the adjusting screw 44 on the breaker arm 45,

and the armature 34 of the magnet is moved by the spring 36 away from the pole pieces the extent required to advance the ratchet 46 one tooth space by the driving spring 41 on the armature. The stone 2| is then released by the discharge pallet in the manner hereinbefore stated and the escape lever I5 is actuated by the main spring H to deliver a power impulse to the balance wheel. The electromagnet 33 is again energized at the termination of the power stroke of the escape lever, and the armature 34 is again swung in the direction of the arrow 42 to return the escape lever to its locked position shown in Figure 2 and to subsequently open the circuit to the electromagnet. It will also be apparent that when the armature 34 of the electromagnet is moved in the direction of the arrow 42, the driving spring 41 is advanced with respect to the ratchet wheel 46 into engagement with the next succeeding tooth on this wheel.

For reasons hereinbefore given, this construction affords extremely accurate performance of the clock mechanism without employing extremely delicate parts in the mechanism and without complicating the nature of the mechanism. As a matter of fact, a clock constructed in accordance with this invention is composed of a in extremely accurate.

relatively few numberv of parts and is capable of being manufactured at a'relatively low cost.

What I claim as my invention is:

1. In clock mechanism, a balancewheel, an electric circuit including an'electromagnet'and aswitch for controlling the circuit, an armature actuated by the electromagnet and supported for movement from an inoperative position in spaced relation to the electromagnet when the circuit is opened 1 to an operative position adjacent the electromagnet when the circuit is closed, means effective in the inoperative position of the armastroke to close the circuit to the electromagnet and effect movement of the armature to its operative position, means actuated by the armature as it is moved to its operative position for returning the escapement lever to its operative position with respect to the balance wheel, means engageable with the escapement lever to latch the same in its operative position, means also actuated by the armature as it is moved toward its operative position toopen the switch in the circuit to the electromagnet after the escapement lever returns to its latched position, means effective upon opening the circuit to move the armature relative tothe escapement lever to its inoperative posi tion, and hand operating means actuated by the armature as it is moved relative to the escapement lever to its inoperativeposition.

2. In clock mechani-m, a balance wheel, hand operating means, an electric circuit including an electromagnet and a switch controlling the circuit to the electromagnet, an armature actuated by the electromagnet and supported for movement from an inoperative position in spaced relation to the electromagnet when the circuit is opened to an operative position adjacent the electromagnet when the circuit is closed, means effective in the inoperative position of the armature to engage the balance wheel and impart a driving impulse to the latter, said last named means including an escapement lever supported for movement relative to the armature and a spring for actuating the escapement lever throughout the-impulse stroke independent of the electromagnet, said escapement lever being releasable from the balance wheel at the termination of the power impulse stroke, said switch comprising cooperating contacts, one of'the contacts carried by the escapement lever for movement as a unit with the lever toward the other contact during the power impulse stroke of the escapement lever and effective to engage said other contact at the end of the power impulse stroke to close the circuit to the electromagnet and effect movement of the armature to its operative position, means actuated by the armature as it is moved toward its operative position to return the escapement lever to its operative position with respect to the balance wheel, means engageable with the escapement lever to latch the same in its operative position, means for opening the circuit to the electromagnet after the escapement lever returns to its latched position, a spring operatively connected to the armature for moving the latter relative to the escapement lever to its inoperative position, and a connection between the armature and hand operating means effective upon movement of the armature rela tive to the escapement lever to actuate said hand operating means.

3. In clock mechanism, a balance wheel, hand operating means, an electric circuit including an electromagnet and a switch for controlling the operation of the electromagnet, an armature actuated by the electromagnet and supported for movement from an inoperative position in spaced relation to the electromagnet when the circuit is opened to an operative position adjacent the electromagnet when the circuit is closed, means urging the armature oi the electromagnet to its inoperative position, a connection between the armature and hand operating means for advancing the latter when the armature is moved to its inoperative position by the second named means, means for actuating the switch to control the circuit to the electromagnet including escapement mechanism having an escapement lever engageable with the balance wheel, means for latching theescapement lever in its operative position relative to the balance wheel, means independent otthe armature for actuating the escapement lever to impart a power impulse to the balance wheel, said escapement lever being releasable from the balance wheel at the termination of the power impulse stroke, said switch comprising cooperating contacts, one of the contacts carried by the escapement lever for movement as a unit, with the lever toward the othercontact during the power impulse stroke oi the escapement lever and effective to engage said other contact at the end of the power impulse stroke to close the circuit to the electromagnet and eflect movement of the armature to its operative position, and means actuated by the armature as it is moved to its operative position for returning the escapement leverto its operative position with respect to the balance wheel.

4. In clock mechanism, a balance wheel, an electric circuit including an electromagnet and a switch for controlling the operation of the eletromagnet, an armature actuated by the electromagnet and supported for movement from an inoperative position in spaced relation to the electromagnet when the circuit is opened to an operative position adiacent the electromagnet when the circuit is closed, means effective in the inoperative position 01' the armature to engage the balance wheel and impart a driving impulse to the latter, said last named means including an escapement lever supported for movement relative to said armature and releasable from the balance wheel at the termination of the power impulse stroke, a contact forming one element of said switch and movable by the escapement lever alter the completion of the power impulse stroke to engage a second cooperating contact element of the switch carried by the armature to close said circuit and eflfect movement 01' the armature to its operative positiomsaid armature operating through the contacts to return the escapement lever to its operative position with respect to the balance wheel, means engageable with the escapement lever to latch the same in its operative position, and means for separating the switch contacts to break the circuit upon movement the escapement lever to its latched position relative to the balance wheel.

5. In clock mechanism, a balance wheel, an electric circuit including an electromagnet and a switch for controlling the operation of the electromagnet, an armature actuated by the electromagnet and supported for movement from an inoperative position spaced from the electromagnet when the circuit is opened to an operative position adjacent the electromagnet when the circuit is closed, means effective in the inoperative position of the armature to engage the balance wheel and impart a driving impulse to the latter, said last named means including an escapement lever supported for movement relative to said armature and releasable from the balance wheel at the termination of the power impulse stroke, a. contact forming one of the cooperating elements of the switch and movable by the escapement lever, a second contact forming the other element of the switch and engaged by the first contact after the escapement lever has completed its power stroke to close the circuit to the electromagnet and thereby eiIect movement of the armature to its operative position, means operated by the armature as it is moved toward its operative position to return the escapement lever to its operative position with respect to the balance wheel, means engageable with the escapement lever to latch the same in its operative position, and means for breaking the circuit to the electromagnet upon movement of the escapement lever to its latched position relative to the balance wheel.

6. In clock mechanism, a balance wheel, hand operating mechanism, an escapement lever supported for swinging movement relative to the balance and having means at the swinging end thereof engageable with the balance, means for swinging the escapement lever in one direction to impart a power impulse to the balance wheel, said escapement lever being releasable from the balance wheel at the termination of the power impulse stroke, means effective at the end of the power impulse stroke of the escapement lever to swing the latter in the opposite direction, means effective upon swinging movement of the escapement lever in the last named direction to latch the escapement lever relative to the balance, means operated by the balance wheel for releasing said latch, and means operating during the interval the escapement lever is latched relative to the balance to advance the hand operating means.

CARLISLE F. MINNEKER. 

